The present invention relates to an improved cloth-laying machine.
By way of background, cloth-laying machines are commonly used whenever layers of cloth have to be deposited on a table for subsequent cutting. In the past, cloth-laying machines had certain characteristics. The side frames of prior machines were generally fabricated from relatively heavy cast iron and/or aluminum. However, in spite of the relatively heavy side frame members, the machine was not sufficiently rigid in the desired directions. In this respect, the side frame members were connected by cross frame members in the nature of tubes, rods or threaded pipes. Such cross frame members permitted the side frame members to tilt from side to side during movement of the cloth-laying machine and also permitted the side frame members to experience relative fore and aft translational movement relative to each other, both of which caused the cloth spreading alignment to be irregular.
Another deficiency of prior cloth laying machines was that they were generally driven by means of toothed or grooved wheels which engaged a mating track suspended at the side of a cutting room table, generally in a cantilevered manner. This was objectionable because a large portion of the weight of the relatively heavy machine and its load of cloth was transferred to the track which was supported by the table in a weak manner. In addition, because of the rigid connection between the drive wheel and the frame of the machine, any undulations in the track were transmitted to the machine, to thereby cause it to move up and down unnecessarily. Conversely, any undulations in the surface of the cloth-laying table could cause the drive wheel to lose engagement with the track.
A further deficiency of prior machines was that the driving of an unequal number of wheels on each side caused an unequal torque or twist to be exerted on the machine, tending to cause it to travel in a nonlinear path. Additionally, if the braking of the carriage was only effected through an unequal number of wheels on the opposite sides of the machine, there could be skidding during braking.
Furthermore, prior machines, which traveled as fast as 300 feet per minute, relied only on a single braking system associated with less than four wheels. If this brake failed, the machine could roll off of the end of the table with its possible consequent destruction and injury to personnel. Furthermore, if the track wheel left the track, the machine would continue in operation in an unguided path, and it could roll off the table if not stopped in time.
In addition, in prior machines a tuck or folding blade and catcher blade assembly was used. The assembly created a fold at the end of machine travel, and the catcher blade held the folded end of the cloth in position. Various types of actuating mechanisms which were similar to the present construction were used in the past. However, the prior actuating mechanisms were not permanently elevated in their entirety above the top of the cloth-laying table and they did not have a lost motion connection associated therewith. The lack of the combination of these features caused prior constructions to be subject to jamming, breakage, or possibly even mismating with the associated part of the catcher with which it was to coact. In situations of this type, there could be severe damage to the machine and/or end catchers.